In the prior art ratchet spanner, the spanner includes a ratchet with teeth and a braking block. The braking block is engaged with the ratchet. A spring serves to latch the block so that the ratchet spanner rotates unidirectionally. However this prior art has completed manufacturing process. Especially the design of the teeth on the ratchet which wastes a larger amount of work. Thus, if the work of forming teeth can be negated, the cost will be reduced greatly and therefore, the price of the ratchet spanner will also be reduced.
In another prior art, a toothless ratchet is developed, but too many elements are used and thus the cost is also high. Thereby it is difficult to update the parts. Furthermore, the structure is not easy to make, such as a round hole is formed for receiving a spring, but this will make the manufacturing process complicated.